<script type="text/javascript" src="jquery.ckeditor.js"></script>
<textarea id="demo1"></textarea>
<br /><br />
<textarea id="demo2"></textarea>
<br /><br />
<textarea id="demo3"></textarea>
<br /><br />
<textarea class="ckeditor"></textarea>

<script type="text/javascript">
CKEDITOR.replace('demo1', { height: 120 })
CKEDITOR.replace('demo2', { toolbar: 'Basic', height: 120 })
CKEDITOR.replace('demo3', { toolbar: 'Full', height: 120 })
</script>